In addition to the mini-episode, a new trailer for the Christmas special - penned by Steven Moffat and expected to air on December 25 - will also be screened, giving viewers another glimpse at new companion Jenna-Louise Coleman.

Of the special, series star Matt Smith said: "It does the sort of wonderful Doctor Who-ey Christmas things - you know, snow, aliens, good will, good cheer, someone trying to take over the world. Hopefully it makes for good Christmas Day telly."